Ectopic overexpression of MucACP-Δ9 desaturase leads to ω-7 fatty acid accumulation in tobacco leaves

MucACP-Delta 9D from cat's claw (Macfadyena unguis-cati) was ectopically overexpressed in tobacco (Nicotiana tabacum L.) leaves to increase the content of omega-7 (omega-7) fatty acids, which have nutraceutical and industrial values for polyethylene and biofuel production. Overexpressed MucACP-Delta 9D localized in the plastid resulted in an increased omega-7 fatty acid (C16:1 Delta 9 and C18:1 Delta 11) content from trace level in the wild type to 25.4-29.7% in the transgenic tobacco leaves. The C16:0, C18:2, and C18:3 fatty acid content decreased by 30-50%, 24%, and 38.7% in the transgenics compared with the wild type, respectively. This evidences that the ectopically expressed MucACP-Delta 9D enzyme actively converts C16:0 to C16:1 Delta 9. MucACP-Delta 9D overexpression in tobacco had no adverse effects on any agronomic traits, including plant growth, development, or seed germination. The present findings provide an excellent germplasm resource and a new technological path for commercial production of valuable fatty acids, using high-biomass vegetative organs of a non-food crop as platforms.